1 /*-
2 * Copyright (c) 1982, 1986, 1989, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * @(#)sys_generic.c 8.5 (Berkeley) 1/21/94
35 */
36
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD: releng/8.2/sys/kern/sys_generic.c 212415 2010-09-10 12:55:36Z kib $");
39
40 #include "opt_compat.h"
41 #include "opt_ktrace.h"
42
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/sysproto.h>
46 #include <sys/filedesc.h>
47 #include <sys/filio.h>
48 #include <sys/fcntl.h>
49 #include <sys/file.h>
50 #include <sys/proc.h>
51 #include <sys/signalvar.h>
52 #include <sys/socketvar.h>
53 #include <sys/uio.h>
54 #include <sys/kernel.h>
55 #include <sys/ktr.h>
56 #include <sys/limits.h>
57 #include <sys/malloc.h>
58 #include <sys/poll.h>
59 #include <sys/resourcevar.h>
60 #include <sys/selinfo.h>
61 #include <sys/sleepqueue.h>
62 #include <sys/syscallsubr.h>
63 #include <sys/sysctl.h>
64 #include <sys/sysent.h>
65 #include <sys/vnode.h>
66 #include <sys/bio.h>
67 #include <sys/buf.h>
68 #include <sys/condvar.h>
69 #ifdef KTRACE
70 #include <sys/ktrace.h>
71 #endif
72
73 #include <security/audit/audit.h>
74
75 static MALLOC_DEFINE(M_IOCTLOPS, "ioctlops", "ioctl data buffer");
76 static MALLOC_DEFINE(M_SELECT, "select", "select() buffer");
77 MALLOC_DEFINE(M_IOV, "iov", "large iov's");
78
79 static int pollout(struct thread *, struct pollfd *, struct pollfd *,
80 u_int);
81 static int pollscan(struct thread *, struct pollfd *, u_int);
82 static int pollrescan(struct thread *);
83 static int selscan(struct thread *, fd_mask **, fd_mask **, int);
84 static int selrescan(struct thread *, fd_mask **, fd_mask **);
85 static void selfdalloc(struct thread *, void *);
86 static void selfdfree(struct seltd *, struct selfd *);
87 static int dofileread(struct thread *, int, struct file *, struct uio *,
88 off_t, int);
89 static int dofilewrite(struct thread *, int, struct file *, struct uio *,
90 off_t, int);
91 static void doselwakeup(struct selinfo *, int);
92 static void seltdinit(struct thread *);
93 static int seltdwait(struct thread *, int);
94 static void seltdclear(struct thread *);
95
96 /*
97 * One seltd per-thread allocated on demand as needed.
98 *
99 * t - protected by st_mtx
100 * k - Only accessed by curthread or read-only
101 */
102 struct seltd {
103 STAILQ_HEAD(, selfd) st_selq; /* (k) List of selfds. */
104 struct selfd *st_free1; /* (k) free fd for read set. */
105 struct selfd *st_free2; /* (k) free fd for write set. */
106 struct mtx st_mtx; /* Protects struct seltd */
107 struct cv st_wait; /* (t) Wait channel. */
108 int st_flags; /* (t) SELTD_ flags. */
109 };
110
111 #define SELTD_PENDING 0x0001 /* We have pending events. */
112 #define SELTD_RESCAN 0x0002 /* Doing a rescan. */
113
114 /*
115 * One selfd allocated per-thread per-file-descriptor.
116 * f - protected by sf_mtx
117 */
118 struct selfd {
119 STAILQ_ENTRY(selfd) sf_link; /* (k) fds owned by this td. */
120 TAILQ_ENTRY(selfd) sf_threads; /* (f) fds on this selinfo. */
121 struct selinfo *sf_si; /* (f) selinfo when linked. */
122 struct mtx *sf_mtx; /* Pointer to selinfo mtx. */
123 struct seltd *sf_td; /* (k) owning seltd. */
124 void *sf_cookie; /* (k) fd or pollfd. */
125 };
126
127 static uma_zone_t selfd_zone;
128 static struct mtx_pool *mtxpool_select;
129
130 #ifndef _SYS_SYSPROTO_H_
131 struct read_args {
132 int fd;
133 void *buf;
134 size_t nbyte;
135 };
136 #endif
137 int
138 read(td, uap)
139 struct thread *td;
140 struct read_args *uap;
141 {
142 struct uio auio;
143 struct iovec aiov;
144 int error;
145
146 if (uap->nbyte > INT_MAX)
147 return (EINVAL);
148 aiov.iov_base = uap->buf;
149 aiov.iov_len = uap->nbyte;
150 auio.uio_iov = &aiov;
151 auio.uio_iovcnt = 1;
152 auio.uio_resid = uap->nbyte;
153 auio.uio_segflg = UIO_USERSPACE;
154 error = kern_readv(td, uap->fd, &auio);
155 return(error);
156 }
157
158 /*
159 * Positioned read system call
160 */
161 #ifndef _SYS_SYSPROTO_H_
162 struct pread_args {
163 int fd;
164 void *buf;
165 size_t nbyte;
166 int pad;
167 off_t offset;
168 };
169 #endif
170 int
171 pread(td, uap)
172 struct thread *td;
173 struct pread_args *uap;
174 {
175 struct uio auio;
176 struct iovec aiov;
177 int error;
178
179 if (uap->nbyte > INT_MAX)
180 return (EINVAL);
181 aiov.iov_base = uap->buf;
182 aiov.iov_len = uap->nbyte;
183 auio.uio_iov = &aiov;
184 auio.uio_iovcnt = 1;
185 auio.uio_resid = uap->nbyte;
186 auio.uio_segflg = UIO_USERSPACE;
187 error = kern_preadv(td, uap->fd, &auio, uap->offset);
188 return(error);
189 }
190
191 int
192 freebsd6_pread(td, uap)
193 struct thread *td;
194 struct freebsd6_pread_args *uap;
195 {
196 struct pread_args oargs;
197
198 oargs.fd = uap->fd;
199 oargs.buf = uap->buf;
200 oargs.nbyte = uap->nbyte;
201 oargs.offset = uap->offset;
202 return (pread(td, &oargs));
203 }
204
205 /*
206 * Scatter read system call.
207 */
208 #ifndef _SYS_SYSPROTO_H_
209 struct readv_args {
210 int fd;
211 struct iovec *iovp;
212 u_int iovcnt;
213 };
214 #endif
215 int
216 readv(struct thread *td, struct readv_args *uap)
217 {
218 struct uio *auio;
219 int error;
220
221 error = copyinuio(uap->iovp, uap->iovcnt, &auio);
222 if (error)
223 return (error);
224 error = kern_readv(td, uap->fd, auio);
225 free(auio, M_IOV);
226 return (error);
227 }
228
229 int
230 kern_readv(struct thread *td, int fd, struct uio *auio)
231 {
232 struct file *fp;
233 int error;
234
235 error = fget_read(td, fd, &fp);
236 if (error)
237 return (error);
238 error = dofileread(td, fd, fp, auio, (off_t)-1, 0);
239 fdrop(fp, td);
240 return (error);
241 }
242
243 /*
244 * Scatter positioned read system call.
245 */
246 #ifndef _SYS_SYSPROTO_H_
247 struct preadv_args {
248 int fd;
249 struct iovec *iovp;
250 u_int iovcnt;
251 off_t offset;
252 };
253 #endif
254 int
255 preadv(struct thread *td, struct preadv_args *uap)
256 {
257 struct uio *auio;
258 int error;
259
260 error = copyinuio(uap->iovp, uap->iovcnt, &auio);
261 if (error)
262 return (error);
263 error = kern_preadv(td, uap->fd, auio, uap->offset);
264 free(auio, M_IOV);
265 return (error);
266 }
267
268 int
269 kern_preadv(td, fd, auio, offset)
270 struct thread *td;
271 int fd;
272 struct uio *auio;
273 off_t offset;
274 {
275 struct file *fp;
276 int error;
277
278 error = fget_read(td, fd, &fp);
279 if (error)
280 return (error);
281 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE))
282 error = ESPIPE;
283 else if (offset < 0 && fp->f_vnode->v_type != VCHR)
284 error = EINVAL;
285 else
286 error = dofileread(td, fd, fp, auio, offset, FOF_OFFSET);
287 fdrop(fp, td);
288 return (error);
289 }
290
291 /*
292 * Common code for readv and preadv that reads data in
293 * from a file using the passed in uio, offset, and flags.
294 */
295 static int
296 dofileread(td, fd, fp, auio, offset, flags)
297 struct thread *td;
298 int fd;
299 struct file *fp;
300 struct uio *auio;
301 off_t offset;
302 int flags;
303 {
304 ssize_t cnt;
305 int error;
306 #ifdef KTRACE
307 struct uio *ktruio = NULL;
308 #endif
309
310 /* Finish zero length reads right here */
311 if (auio->uio_resid == 0) {
312 td->td_retval[0] = 0;
313 return(0);
314 }
315 auio->uio_rw = UIO_READ;
316 auio->uio_offset = offset;
317 auio->uio_td = td;
318 #ifdef KTRACE
319 if (KTRPOINT(td, KTR_GENIO))
320 ktruio = cloneuio(auio);
321 #endif
322 cnt = auio->uio_resid;
323 if ((error = fo_read(fp, auio, td->td_ucred, flags, td))) {
324 if (auio->uio_resid != cnt && (error == ERESTART ||
325 error == EINTR || error == EWOULDBLOCK))
326 error = 0;
327 }
328 cnt -= auio->uio_resid;
329 #ifdef KTRACE
330 if (ktruio != NULL) {
331 ktruio->uio_resid = cnt;
332 ktrgenio(fd, UIO_READ, ktruio, error);
333 }
334 #endif
335 td->td_retval[0] = cnt;
336 return (error);
337 }
338
339 #ifndef _SYS_SYSPROTO_H_
340 struct write_args {
341 int fd;
342 const void *buf;
343 size_t nbyte;
344 };
345 #endif
346 int
347 write(td, uap)
348 struct thread *td;
349 struct write_args *uap;
350 {
351 struct uio auio;
352 struct iovec aiov;
353 int error;
354
355 if (uap->nbyte > INT_MAX)
356 return (EINVAL);
357 aiov.iov_base = (void *)(uintptr_t)uap->buf;
358 aiov.iov_len = uap->nbyte;
359 auio.uio_iov = &aiov;
360 auio.uio_iovcnt = 1;
361 auio.uio_resid = uap->nbyte;
362 auio.uio_segflg = UIO_USERSPACE;
363 error = kern_writev(td, uap->fd, &auio);
364 return(error);
365 }
366
367 /*
368 * Positioned write system call.
369 */
370 #ifndef _SYS_SYSPROTO_H_
371 struct pwrite_args {
372 int fd;
373 const void *buf;
374 size_t nbyte;
375 int pad;
376 off_t offset;
377 };
378 #endif
379 int
380 pwrite(td, uap)
381 struct thread *td;
382 struct pwrite_args *uap;
383 {
384 struct uio auio;
385 struct iovec aiov;
386 int error;
387
388 if (uap->nbyte > INT_MAX)
389 return (EINVAL);
390 aiov.iov_base = (void *)(uintptr_t)uap->buf;
391 aiov.iov_len = uap->nbyte;
392 auio.uio_iov = &aiov;
393 auio.uio_iovcnt = 1;
394 auio.uio_resid = uap->nbyte;
395 auio.uio_segflg = UIO_USERSPACE;
396 error = kern_pwritev(td, uap->fd, &auio, uap->offset);
397 return(error);
398 }
399
400 int
401 freebsd6_pwrite(td, uap)
402 struct thread *td;
403 struct freebsd6_pwrite_args *uap;
404 {
405 struct pwrite_args oargs;
406
407 oargs.fd = uap->fd;
408 oargs.buf = uap->buf;
409 oargs.nbyte = uap->nbyte;
410 oargs.offset = uap->offset;
411 return (pwrite(td, &oargs));
412 }
413
414 /*
415 * Gather write system call.
416 */
417 #ifndef _SYS_SYSPROTO_H_
418 struct writev_args {
419 int fd;
420 struct iovec *iovp;
421 u_int iovcnt;
422 };
423 #endif
424 int
425 writev(struct thread *td, struct writev_args *uap)
426 {
427 struct uio *auio;
428 int error;
429
430 error = copyinuio(uap->iovp, uap->iovcnt, &auio);
431 if (error)
432 return (error);
433 error = kern_writev(td, uap->fd, auio);
434 free(auio, M_IOV);
435 return (error);
436 }
437
438 int
439 kern_writev(struct thread *td, int fd, struct uio *auio)
440 {
441 struct file *fp;
442 int error;
443
444 error = fget_write(td, fd, &fp);
445 if (error)
446 return (error);
447 error = dofilewrite(td, fd, fp, auio, (off_t)-1, 0);
448 fdrop(fp, td);
449 return (error);
450 }
451
452 /*
453 * Gather positioned write system call.
454 */
455 #ifndef _SYS_SYSPROTO_H_
456 struct pwritev_args {
457 int fd;
458 struct iovec *iovp;
459 u_int iovcnt;
460 off_t offset;
461 };
462 #endif
463 int
464 pwritev(struct thread *td, struct pwritev_args *uap)
465 {
466 struct uio *auio;
467 int error;
468
469 error = copyinuio(uap->iovp, uap->iovcnt, &auio);
470 if (error)
471 return (error);
472 error = kern_pwritev(td, uap->fd, auio, uap->offset);
473 free(auio, M_IOV);
474 return (error);
475 }
476
477 int
478 kern_pwritev(td, fd, auio, offset)
479 struct thread *td;
480 struct uio *auio;
481 int fd;
482 off_t offset;
483 {
484 struct file *fp;
485 int error;
486
487 error = fget_write(td, fd, &fp);
488 if (error)
489 return (error);
490 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE))
491 error = ESPIPE;
492 else if (offset < 0 && fp->f_vnode->v_type != VCHR)
493 error = EINVAL;
494 else
495 error = dofilewrite(td, fd, fp, auio, offset, FOF_OFFSET);
496 fdrop(fp, td);
497 return (error);
498 }
499
500 /*
501 * Common code for writev and pwritev that writes data to
502 * a file using the passed in uio, offset, and flags.
503 */
504 static int
505 dofilewrite(td, fd, fp, auio, offset, flags)
506 struct thread *td;
507 int fd;
508 struct file *fp;
509 struct uio *auio;
510 off_t offset;
511 int flags;
512 {
513 ssize_t cnt;
514 int error;
515 #ifdef KTRACE
516 struct uio *ktruio = NULL;
517 #endif
518
519 auio->uio_rw = UIO_WRITE;
520 auio->uio_td = td;
521 auio->uio_offset = offset;
522 #ifdef KTRACE
523 if (KTRPOINT(td, KTR_GENIO))
524 ktruio = cloneuio(auio);
525 #endif
526 cnt = auio->uio_resid;
527 if (fp->f_type == DTYPE_VNODE)
528 bwillwrite();
529 if ((error = fo_write(fp, auio, td->td_ucred, flags, td))) {
530 if (auio->uio_resid != cnt && (error == ERESTART ||
531 error == EINTR || error == EWOULDBLOCK))
532 error = 0;
533 /* Socket layer is responsible for issuing SIGPIPE. */
534 if (fp->f_type != DTYPE_SOCKET && error == EPIPE) {
535 PROC_LOCK(td->td_proc);
536 tdksignal(td, SIGPIPE, NULL);
537 PROC_UNLOCK(td->td_proc);
538 }
539 }
540 cnt -= auio->uio_resid;
541 #ifdef KTRACE
542 if (ktruio != NULL) {
543 ktruio->uio_resid = cnt;
544 ktrgenio(fd, UIO_WRITE, ktruio, error);
545 }
546 #endif
547 td->td_retval[0] = cnt;
548 return (error);
549 }
550
551 /*
552 * Truncate a file given a file descriptor.
553 *
554 * Can't use fget_write() here, since must return EINVAL and not EBADF if the
555 * descriptor isn't writable.
556 */
557 int
558 kern_ftruncate(td, fd, length)
559 struct thread *td;
560 int fd;
561 off_t length;
562 {
563 struct file *fp;
564 int error;
565
566 AUDIT_ARG_FD(fd);
567 if (length < 0)
568 return (EINVAL);
569 error = fget(td, fd, &fp);
570 if (error)
571 return (error);
572 AUDIT_ARG_FILE(td->td_proc, fp);
573 if (!(fp->f_flag & FWRITE)) {
574 fdrop(fp, td);
575 return (EINVAL);
576 }
577 error = fo_truncate(fp, length, td->td_ucred, td);
578 fdrop(fp, td);
579 return (error);
580 }
581
582 #ifndef _SYS_SYSPROTO_H_
583 struct ftruncate_args {
584 int fd;
585 int pad;
586 off_t length;
587 };
588 #endif
589 int
590 ftruncate(td, uap)
591 struct thread *td;
592 struct ftruncate_args *uap;
593 {
594
595 return (kern_ftruncate(td, uap->fd, uap->length));
596 }
597
598 #if defined(COMPAT_43)
599 #ifndef _SYS_SYSPROTO_H_
600 struct oftruncate_args {
601 int fd;
602 long length;
603 };
604 #endif
605 int
606 oftruncate(td, uap)
607 struct thread *td;
608 struct oftruncate_args *uap;
609 {
610
611 return (kern_ftruncate(td, uap->fd, uap->length));
612 }
613 #endif /* COMPAT_43 */
614
615 #ifndef _SYS_SYSPROTO_H_
616 struct ioctl_args {
617 int fd;
618 u_long com;
619 caddr_t data;
620 };
621 #endif
622 /* ARGSUSED */
623 int
624 ioctl(struct thread *td, struct ioctl_args *uap)
625 {
626 u_long com;
627 int arg, error;
628 u_int size;
629 caddr_t data;
630
631 if (uap->com > 0xffffffff) {
632 printf(
633 "WARNING pid %d (%s): ioctl sign-extension ioctl %lx\n",
634 td->td_proc->p_pid, td->td_name, uap->com);
635 uap->com &= 0xffffffff;
636 }
637 com = uap->com;
638
639 /*
640 * Interpret high order word to find amount of data to be
641 * copied to/from the user's address space.
642 */
643 size = IOCPARM_LEN(com);
644 if ((size > IOCPARM_MAX) ||
645 ((com & (IOC_VOID | IOC_IN | IOC_OUT)) == 0) ||
646 #if defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) || defined(COMPAT_43)
647 ((com & IOC_OUT) && size == 0) ||
648 #else
649 ((com & (IOC_IN | IOC_OUT)) && size == 0) ||
650 #endif
651 ((com & IOC_VOID) && size > 0 && size != sizeof(int)))
652 return (ENOTTY);
653
654 if (size > 0) {
655 if (com & IOC_VOID) {
656 /* Integer argument. */
657 arg = (intptr_t)uap->data;
658 data = (void *)&arg;
659 size = 0;
660 } else
661 data = malloc((u_long)size, M_IOCTLOPS, M_WAITOK);
662 } else
663 data = (void *)&uap->data;
664 if (com & IOC_IN) {
665 error = copyin(uap->data, data, (u_int)size);
666 if (error) {
667 if (size > 0)
668 free(data, M_IOCTLOPS);
669 return (error);
670 }
671 } else if (com & IOC_OUT) {
672 /*
673 * Zero the buffer so the user always
674 * gets back something deterministic.
675 */
676 bzero(data, size);
677 }
678
679 error = kern_ioctl(td, uap->fd, com, data);
680
681 if (error == 0 && (com & IOC_OUT))
682 error = copyout(data, uap->data, (u_int)size);
683
684 if (size > 0)
685 free(data, M_IOCTLOPS);
686 return (error);
687 }
688
689 int
690 kern_ioctl(struct thread *td, int fd, u_long com, caddr_t data)
691 {
692 struct file *fp;
693 struct filedesc *fdp;
694 int error;
695 int tmp;
696
697 AUDIT_ARG_FD(fd);
698 AUDIT_ARG_CMD(com);
699 if ((error = fget(td, fd, &fp)) != 0)
700 return (error);
701 if ((fp->f_flag & (FREAD | FWRITE)) == 0) {
702 fdrop(fp, td);
703 return (EBADF);
704 }
705 fdp = td->td_proc->p_fd;
706 switch (com) {
707 case FIONCLEX:
708 FILEDESC_XLOCK(fdp);
709 fdp->fd_ofileflags[fd] &= ~UF_EXCLOSE;
710 FILEDESC_XUNLOCK(fdp);
711 goto out;
712 case FIOCLEX:
713 FILEDESC_XLOCK(fdp);
714 fdp->fd_ofileflags[fd] |= UF_EXCLOSE;
715 FILEDESC_XUNLOCK(fdp);
716 goto out;
717 case FIONBIO:
718 if ((tmp = *(int *)data))
719 atomic_set_int(&fp->f_flag, FNONBLOCK);
720 else
721 atomic_clear_int(&fp->f_flag, FNONBLOCK);
722 data = (void *)&tmp;
723 break;
724 case FIOASYNC:
725 if ((tmp = *(int *)data))
726 atomic_set_int(&fp->f_flag, FASYNC);
727 else
728 atomic_clear_int(&fp->f_flag, FASYNC);
729 data = (void *)&tmp;
730 break;
731 }
732
733 error = fo_ioctl(fp, com, data, td->td_ucred, td);
734 out:
735 fdrop(fp, td);
736 return (error);
737 }
738
739 int
740 poll_no_poll(int events)
741 {
742 /*
743 * Return true for read/write. If the user asked for something
744 * special, return POLLNVAL, so that clients have a way of
745 * determining reliably whether or not the extended
746 * functionality is present without hard-coding knowledge
747 * of specific filesystem implementations.
748 */
749 if (events & ~POLLSTANDARD)
750 return (POLLNVAL);
751
752 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
753 }
754
755 int
756 pselect(struct thread *td, struct pselect_args *uap)
757 {
758 struct timespec ts;
759 struct timeval tv, *tvp;
760 sigset_t set, *uset;
761 int error;
762
763 if (uap->ts != NULL) {
764 error = copyin(uap->ts, &ts, sizeof(ts));
765 if (error != 0)
766 return (error);
767 TIMESPEC_TO_TIMEVAL(&tv, &ts);
768 tvp = &tv;
769 } else
770 tvp = NULL;
771 if (uap->sm != NULL) {
772 error = copyin(uap->sm, &set, sizeof(set));
773 if (error != 0)
774 return (error);
775 uset = &set;
776 } else
777 uset = NULL;
778 return (kern_pselect(td, uap->nd, uap->in, uap->ou, uap->ex, tvp,
779 uset, NFDBITS));
780 }
781
782 int
783 kern_pselect(struct thread *td, int nd, fd_set *in, fd_set *ou, fd_set *ex,
784 struct timeval *tvp, sigset_t *uset, int abi_nfdbits)
785 {
786 int error;
787
788 if (uset != NULL) {
789 error = kern_sigprocmask(td, SIG_SETMASK, uset,
790 &td->td_oldsigmask, 0);
791 if (error != 0)
792 return (error);
793 td->td_pflags |= TDP_OLDMASK;
794 /*
795 * Make sure that ast() is called on return to
796 * usermode and TDP_OLDMASK is cleared, restoring old
797 * sigmask.
798 */
799 thread_lock(td);
800 td->td_flags |= TDF_ASTPENDING;
801 thread_unlock(td);
802 }
803 error = kern_select(td, nd, in, ou, ex, tvp, abi_nfdbits);
804 return (error);
805 }
806
807 #ifndef _SYS_SYSPROTO_H_
808 struct select_args {
809 int nd;
810 fd_set *in, *ou, *ex;
811 struct timeval *tv;
812 };
813 #endif
814 int
815 select(struct thread *td, struct select_args *uap)
816 {
817 struct timeval tv, *tvp;
818 int error;
819
820 if (uap->tv != NULL) {
821 error = copyin(uap->tv, &tv, sizeof(tv));
822 if (error)
823 return (error);
824 tvp = &tv;
825 } else
826 tvp = NULL;
827
828 return (kern_select(td, uap->nd, uap->in, uap->ou, uap->ex, tvp,
829 NFDBITS));
830 }
831
832 int
833 kern_select(struct thread *td, int nd, fd_set *fd_in, fd_set *fd_ou,
834 fd_set *fd_ex, struct timeval *tvp, int abi_nfdbits)
835 {
836 struct filedesc *fdp;
837 /*
838 * The magic 2048 here is chosen to be just enough for FD_SETSIZE
839 * infds with the new FD_SETSIZE of 1024, and more than enough for
840 * FD_SETSIZE infds, outfds and exceptfds with the old FD_SETSIZE
841 * of 256.
842 */
843 fd_mask s_selbits[howmany(2048, NFDBITS)];
844 fd_mask *ibits[3], *obits[3], *selbits, *sbp;
845 struct timeval atv, rtv, ttv;
846 int error, timo;
847 u_int nbufbytes, ncpbytes, ncpubytes, nfdbits;
848
849 if (nd < 0)
850 return (EINVAL);
851 fdp = td->td_proc->p_fd;
852 if (nd > fdp->fd_lastfile + 1)
853 nd = fdp->fd_lastfile + 1;
854
855 /*
856 * Allocate just enough bits for the non-null fd_sets. Use the
857 * preallocated auto buffer if possible.
858 */
859 nfdbits = roundup(nd, NFDBITS);
860 ncpbytes = nfdbits / NBBY;
861 ncpubytes = roundup(nd, abi_nfdbits) / NBBY;
862 nbufbytes = 0;
863 if (fd_in != NULL)
864 nbufbytes += 2 * ncpbytes;
865 if (fd_ou != NULL)
866 nbufbytes += 2 * ncpbytes;
867 if (fd_ex != NULL)
868 nbufbytes += 2 * ncpbytes;
869 if (nbufbytes <= sizeof s_selbits)
870 selbits = &s_selbits[0];
871 else
872 selbits = malloc(nbufbytes, M_SELECT, M_WAITOK);
873
874 /*
875 * Assign pointers into the bit buffers and fetch the input bits.
876 * Put the output buffers together so that they can be bzeroed
877 * together.
878 */
879 sbp = selbits;
880 #define getbits(name, x) \
881 do { \
882 if (name == NULL) { \
883 ibits[x] = NULL; \
884 obits[x] = NULL; \
885 } else { \
886 ibits[x] = sbp + nbufbytes / 2 / sizeof *sbp; \
887 obits[x] = sbp; \
888 sbp += ncpbytes / sizeof *sbp; \
889 error = copyin(name, ibits[x], ncpubytes); \
890 if (error != 0) \
891 goto done; \
892 bzero((char *)ibits[x] + ncpubytes, \
893 ncpbytes - ncpubytes); \
894 } \
895 } while (0)
896 getbits(fd_in, 0);
897 getbits(fd_ou, 1);
898 getbits(fd_ex, 2);
899 #undef getbits
900
901 #if BYTE_ORDER == BIG_ENDIAN && defined(__LP64__)
902 /*
903 * XXX: swizzle_fdset assumes that if abi_nfdbits != NFDBITS,
904 * we are running under 32-bit emulation. This should be more
905 * generic.
906 */
907 #define swizzle_fdset(bits) \
908 if (abi_nfdbits != NFDBITS && bits != NULL) { \
909 int i; \
910 for (i = 0; i < ncpbytes / sizeof *sbp; i++) \
911 bits[i] = (bits[i] >> 32) | (bits[i] << 32); \
912 }
913 #else
914 #define swizzle_fdset(bits)
915 #endif
916
917 /* Make sure the bit order makes it through an ABI transition */
918 swizzle_fdset(ibits[0]);
919 swizzle_fdset(ibits[1]);
920 swizzle_fdset(ibits[2]);
921
922 if (nbufbytes != 0)
923 bzero(selbits, nbufbytes / 2);
924
925 if (tvp != NULL) {
926 atv = *tvp;
927 if (itimerfix(&atv)) {
928 error = EINVAL;
929 goto done;
930 }
931 getmicrouptime(&rtv);
932 timevaladd(&atv, &rtv);
933 } else {
934 atv.tv_sec = 0;
935 atv.tv_usec = 0;
936 }
937 timo = 0;
938 seltdinit(td);
939 /* Iterate until the timeout expires or descriptors become ready. */
940 for (;;) {
941 error = selscan(td, ibits, obits, nd);
942 if (error || td->td_retval[0] != 0)
943 break;
944 if (atv.tv_sec || atv.tv_usec) {
945 getmicrouptime(&rtv);
946 if (timevalcmp(&rtv, &atv, >=))
947 break;
948 ttv = atv;
949 timevalsub(&ttv, &rtv);
950 timo = ttv.tv_sec > 24 * 60 * 60 ?
951 24 * 60 * 60 * hz : tvtohz(&ttv);
952 }
953 error = seltdwait(td, timo);
954 if (error)
955 break;
956 error = selrescan(td, ibits, obits);
957 if (error || td->td_retval[0] != 0)
958 break;
959 }
960 seltdclear(td);
961
962 done:
963 /* select is not restarted after signals... */
964 if (error == ERESTART)
965 error = EINTR;
966 if (error == EWOULDBLOCK)
967 error = 0;
968
969 /* swizzle bit order back, if necessary */
970 swizzle_fdset(obits[0]);
971 swizzle_fdset(obits[1]);
972 swizzle_fdset(obits[2]);
973 #undef swizzle_fdset
974
975 #define putbits(name, x) \
976 if (name && (error2 = copyout(obits[x], name, ncpubytes))) \
977 error = error2;
978 if (error == 0) {
979 int error2;
980
981 putbits(fd_in, 0);
982 putbits(fd_ou, 1);
983 putbits(fd_ex, 2);
984 #undef putbits
985 }
986 if (selbits != &s_selbits[0])
987 free(selbits, M_SELECT);
988
989 return (error);
990 }
991 /*
992 * Convert a select bit set to poll flags.
993 *
994 * The backend always returns POLLHUP/POLLERR if appropriate and we
995 * return this as a set bit in any set.
996 */
997 static int select_flags[3] = {
998 POLLRDNORM | POLLHUP | POLLERR,
999 POLLWRNORM | POLLHUP | POLLERR,
1000 POLLRDBAND | POLLERR
1001 };
1002
1003 /*
1004 * Compute the fo_poll flags required for a fd given by the index and
1005 * bit position in the fd_mask array.
1006 */
1007 static __inline int
1008 selflags(fd_mask **ibits, int idx, fd_mask bit)
1009 {
1010 int flags;
1011 int msk;
1012
1013 flags = 0;
1014 for (msk = 0; msk < 3; msk++) {
1015 if (ibits[msk] == NULL)
1016 continue;
1017 if ((ibits[msk][idx] & bit) == 0)
1018 continue;
1019 flags |= select_flags[msk];
1020 }
1021 return (flags);
1022 }
1023
1024 /*
1025 * Set the appropriate output bits given a mask of fired events and the
1026 * input bits originally requested.
1027 */
1028 static __inline int
1029 selsetbits(fd_mask **ibits, fd_mask **obits, int idx, fd_mask bit, int events)
1030 {
1031 int msk;
1032 int n;
1033
1034 n = 0;
1035 for (msk = 0; msk < 3; msk++) {
1036 if ((events & select_flags[msk]) == 0)
1037 continue;
1038 if (ibits[msk] == NULL)
1039 continue;
1040 if ((ibits[msk][idx] & bit) == 0)
1041 continue;
1042 /*
1043 * XXX Check for a duplicate set. This can occur because a
1044 * socket calls selrecord() twice for each poll() call
1045 * resulting in two selfds per real fd. selrescan() will
1046 * call selsetbits twice as a result.
1047 */
1048 if ((obits[msk][idx] & bit) != 0)
1049 continue;
1050 obits[msk][idx] |= bit;
1051 n++;
1052 }
1053
1054 return (n);
1055 }
1056
1057 /*
1058 * Traverse the list of fds attached to this thread's seltd and check for
1059 * completion.
1060 */
1061 static int
1062 selrescan(struct thread *td, fd_mask **ibits, fd_mask **obits)
1063 {
1064 struct filedesc *fdp;
1065 struct selinfo *si;
1066 struct seltd *stp;
1067 struct selfd *sfp;
1068 struct selfd *sfn;
1069 struct file *fp;
1070 fd_mask bit;
1071 int fd, ev, n, idx;
1072
1073 fdp = td->td_proc->p_fd;
1074 stp = td->td_sel;
1075 n = 0;
1076 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) {
1077 fd = (int)(uintptr_t)sfp->sf_cookie;
1078 si = sfp->sf_si;
1079 selfdfree(stp, sfp);
1080 /* If the selinfo wasn't cleared the event didn't fire. */
1081 if (si != NULL)
1082 continue;
1083 if ((fp = fget_unlocked(fdp, fd)) == NULL)
1084 return (EBADF);
1085 idx = fd / NFDBITS;
1086 bit = (fd_mask)1 << (fd % NFDBITS);
1087 ev = fo_poll(fp, selflags(ibits, idx, bit), td->td_ucred, td);
1088 fdrop(fp, td);
1089 if (ev != 0)
1090 n += selsetbits(ibits, obits, idx, bit, ev);
1091 }
1092 stp->st_flags = 0;
1093 td->td_retval[0] = n;
1094 return (0);
1095 }
1096
1097 /*
1098 * Perform the initial filedescriptor scan and register ourselves with
1099 * each selinfo.
1100 */
1101 static int
1102 selscan(td, ibits, obits, nfd)
1103 struct thread *td;
1104 fd_mask **ibits, **obits;
1105 int nfd;
1106 {
1107 struct filedesc *fdp;
1108 struct file *fp;
1109 fd_mask bit;
1110 int ev, flags, end, fd;
1111 int n, idx;
1112
1113 fdp = td->td_proc->p_fd;
1114 n = 0;
1115 for (idx = 0, fd = 0; fd < nfd; idx++) {
1116 end = imin(fd + NFDBITS, nfd);
1117 for (bit = 1; fd < end; bit <<= 1, fd++) {
1118 /* Compute the list of events we're interested in. */
1119 flags = selflags(ibits, idx, bit);
1120 if (flags == 0)
1121 continue;
1122 if ((fp = fget_unlocked(fdp, fd)) == NULL)
1123 return (EBADF);
1124 selfdalloc(td, (void *)(uintptr_t)fd);
1125 ev = fo_poll(fp, flags, td->td_ucred, td);
1126 fdrop(fp, td);
1127 if (ev != 0)
1128 n += selsetbits(ibits, obits, idx, bit, ev);
1129 }
1130 }
1131
1132 td->td_retval[0] = n;
1133 return (0);
1134 }
1135
1136 #ifndef _SYS_SYSPROTO_H_
1137 struct poll_args {
1138 struct pollfd *fds;
1139 u_int nfds;
1140 int timeout;
1141 };
1142 #endif
1143 int
1144 poll(td, uap)
1145 struct thread *td;
1146 struct poll_args *uap;
1147 {
1148 struct pollfd *bits;
1149 struct pollfd smallbits[32];
1150 struct timeval atv, rtv, ttv;
1151 int error = 0, timo;
1152 u_int nfds;
1153 size_t ni;
1154
1155 nfds = uap->nfds;
1156 if (nfds > maxfilesperproc && nfds > FD_SETSIZE)
1157 return (EINVAL);
1158 ni = nfds * sizeof(struct pollfd);
1159 if (ni > sizeof(smallbits))
1160 bits = malloc(ni, M_TEMP, M_WAITOK);
1161 else
1162 bits = smallbits;
1163 error = copyin(uap->fds, bits, ni);
1164 if (error)
1165 goto done;
1166 if (uap->timeout != INFTIM) {
1167 atv.tv_sec = uap->timeout / 1000;
1168 atv.tv_usec = (uap->timeout % 1000) * 1000;
1169 if (itimerfix(&atv)) {
1170 error = EINVAL;
1171 goto done;
1172 }
1173 getmicrouptime(&rtv);
1174 timevaladd(&atv, &rtv);
1175 } else {
1176 atv.tv_sec = 0;
1177 atv.tv_usec = 0;
1178 }
1179 timo = 0;
1180 seltdinit(td);
1181 /* Iterate until the timeout expires or descriptors become ready. */
1182 for (;;) {
1183 error = pollscan(td, bits, nfds);
1184 if (error || td->td_retval[0] != 0)
1185 break;
1186 if (atv.tv_sec || atv.tv_usec) {
1187 getmicrouptime(&rtv);
1188 if (timevalcmp(&rtv, &atv, >=))
1189 break;
1190 ttv = atv;
1191 timevalsub(&ttv, &rtv);
1192 timo = ttv.tv_sec > 24 * 60 * 60 ?
1193 24 * 60 * 60 * hz : tvtohz(&ttv);
1194 }
1195 error = seltdwait(td, timo);
1196 if (error)
1197 break;
1198 error = pollrescan(td);
1199 if (error || td->td_retval[0] != 0)
1200 break;
1201 }
1202 seltdclear(td);
1203
1204 done:
1205 /* poll is not restarted after signals... */
1206 if (error == ERESTART)
1207 error = EINTR;
1208 if (error == EWOULDBLOCK)
1209 error = 0;
1210 if (error == 0) {
1211 error = pollout(td, bits, uap->fds, nfds);
1212 if (error)
1213 goto out;
1214 }
1215 out:
1216 if (ni > sizeof(smallbits))
1217 free(bits, M_TEMP);
1218 return (error);
1219 }
1220
1221 static int
1222 pollrescan(struct thread *td)
1223 {
1224 struct seltd *stp;
1225 struct selfd *sfp;
1226 struct selfd *sfn;
1227 struct selinfo *si;
1228 struct filedesc *fdp;
1229 struct file *fp;
1230 struct pollfd *fd;
1231 int n;
1232
1233 n = 0;
1234 fdp = td->td_proc->p_fd;
1235 stp = td->td_sel;
1236 FILEDESC_SLOCK(fdp);
1237 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) {
1238 fd = (struct pollfd *)sfp->sf_cookie;
1239 si = sfp->sf_si;
1240 selfdfree(stp, sfp);
1241 /* If the selinfo wasn't cleared the event didn't fire. */
1242 if (si != NULL)
1243 continue;
1244 fp = fdp->fd_ofiles[fd->fd];
1245 if (fp == NULL) {
1246 fd->revents = POLLNVAL;
1247 n++;
1248 continue;
1249 }
1250 /*
1251 * Note: backend also returns POLLHUP and
1252 * POLLERR if appropriate.
1253 */
1254 fd->revents = fo_poll(fp, fd->events, td->td_ucred, td);
1255 if (fd->revents != 0)
1256 n++;
1257 }
1258 FILEDESC_SUNLOCK(fdp);
1259 stp->st_flags = 0;
1260 td->td_retval[0] = n;
1261 return (0);
1262 }
1263
1264
1265 static int
1266 pollout(td, fds, ufds, nfd)
1267 struct thread *td;
1268 struct pollfd *fds;
1269 struct pollfd *ufds;
1270 u_int nfd;
1271 {
1272 int error = 0;
1273 u_int i = 0;
1274 u_int n = 0;
1275
1276 for (i = 0; i < nfd; i++) {
1277 error = copyout(&fds->revents, &ufds->revents,
1278 sizeof(ufds->revents));
1279 if (error)
1280 return (error);
1281 if (fds->revents != 0)
1282 n++;
1283 fds++;
1284 ufds++;
1285 }
1286 td->td_retval[0] = n;
1287 return (0);
1288 }
1289
1290 static int
1291 pollscan(td, fds, nfd)
1292 struct thread *td;
1293 struct pollfd *fds;
1294 u_int nfd;
1295 {
1296 struct filedesc *fdp = td->td_proc->p_fd;
1297 int i;
1298 struct file *fp;
1299 int n = 0;
1300
1301 FILEDESC_SLOCK(fdp);
1302 for (i = 0; i < nfd; i++, fds++) {
1303 if (fds->fd >= fdp->fd_nfiles) {
1304 fds->revents = POLLNVAL;
1305 n++;
1306 } else if (fds->fd < 0) {
1307 fds->revents = 0;
1308 } else {
1309 fp = fdp->fd_ofiles[fds->fd];
1310 if (fp == NULL) {
1311 fds->revents = POLLNVAL;
1312 n++;
1313 } else {
1314 /*
1315 * Note: backend also returns POLLHUP and
1316 * POLLERR if appropriate.
1317 */
1318 selfdalloc(td, fds);
1319 fds->revents = fo_poll(fp, fds->events,
1320 td->td_ucred, td);
1321 /*
1322 * POSIX requires POLLOUT to be never
1323 * set simultaneously with POLLHUP.
1324 */
1325 if ((fds->revents & POLLHUP) != 0)
1326 fds->revents &= ~POLLOUT;
1327
1328 if (fds->revents != 0)
1329 n++;
1330 }
1331 }
1332 }
1333 FILEDESC_SUNLOCK(fdp);
1334 td->td_retval[0] = n;
1335 return (0);
1336 }
1337
1338 /*
1339 * OpenBSD poll system call.
1340 *
1341 * XXX this isn't quite a true representation.. OpenBSD uses select ops.
1342 */
1343 #ifndef _SYS_SYSPROTO_H_
1344 struct openbsd_poll_args {
1345 struct pollfd *fds;
1346 u_int nfds;
1347 int timeout;
1348 };
1349 #endif
1350 int
1351 openbsd_poll(td, uap)
1352 register struct thread *td;
1353 register struct openbsd_poll_args *uap;
1354 {
1355 return (poll(td, (struct poll_args *)uap));
1356 }
1357
1358 /*
1359 * XXX This was created specifically to support netncp and netsmb. This
1360 * allows the caller to specify a socket to wait for events on. It returns
1361 * 0 if any events matched and an error otherwise. There is no way to
1362 * determine which events fired.
1363 */
1364 int
1365 selsocket(struct socket *so, int events, struct timeval *tvp, struct thread *td)
1366 {
1367 struct timeval atv, rtv, ttv;
1368 int error, timo;
1369
1370 if (tvp != NULL) {
1371 atv = *tvp;
1372 if (itimerfix(&atv))
1373 return (EINVAL);
1374 getmicrouptime(&rtv);
1375 timevaladd(&atv, &rtv);
1376 } else {
1377 atv.tv_sec = 0;
1378 atv.tv_usec = 0;
1379 }
1380
1381 timo = 0;
1382 seltdinit(td);
1383 /*
1384 * Iterate until the timeout expires or the socket becomes ready.
1385 */
1386 for (;;) {
1387 selfdalloc(td, NULL);
1388 error = sopoll(so, events, NULL, td);
1389 /* error here is actually the ready events. */
1390 if (error)
1391 return (0);
1392 if (atv.tv_sec || atv.tv_usec) {
1393 getmicrouptime(&rtv);
1394 if (timevalcmp(&rtv, &atv, >=)) {
1395 seltdclear(td);
1396 return (EWOULDBLOCK);
1397 }
1398 ttv = atv;
1399 timevalsub(&ttv, &rtv);
1400 timo = ttv.tv_sec > 24 * 60 * 60 ?
1401 24 * 60 * 60 * hz : tvtohz(&ttv);
1402 }
1403 error = seltdwait(td, timo);
1404 seltdclear(td);
1405 if (error)
1406 break;
1407 }
1408 /* XXX Duplicates ncp/smb behavior. */
1409 if (error == ERESTART)
1410 error = 0;
1411 return (error);
1412 }
1413
1414 /*
1415 * Preallocate two selfds associated with 'cookie'. Some fo_poll routines
1416 * have two select sets, one for read and another for write.
1417 */
1418 static void
1419 selfdalloc(struct thread *td, void *cookie)
1420 {
1421 struct seltd *stp;
1422
1423 stp = td->td_sel;
1424 if (stp->st_free1 == NULL)
1425 stp->st_free1 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO);
1426 stp->st_free1->sf_td = stp;
1427 stp->st_free1->sf_cookie = cookie;
1428 if (stp->st_free2 == NULL)
1429 stp->st_free2 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO);
1430 stp->st_free2->sf_td = stp;
1431 stp->st_free2->sf_cookie = cookie;
1432 }
1433
1434 static void
1435 selfdfree(struct seltd *stp, struct selfd *sfp)
1436 {
1437 STAILQ_REMOVE(&stp->st_selq, sfp, selfd, sf_link);
1438 mtx_lock(sfp->sf_mtx);
1439 if (sfp->sf_si)
1440 TAILQ_REMOVE(&sfp->sf_si->si_tdlist, sfp, sf_threads);
1441 mtx_unlock(sfp->sf_mtx);
1442 uma_zfree(selfd_zone, sfp);
1443 }
1444
1445 /*
1446 * Record a select request.
1447 */
1448 void
1449 selrecord(selector, sip)
1450 struct thread *selector;
1451 struct selinfo *sip;
1452 {
1453 struct selfd *sfp;
1454 struct seltd *stp;
1455 struct mtx *mtxp;
1456
1457 stp = selector->td_sel;
1458 /*
1459 * Don't record when doing a rescan.
1460 */
1461 if (stp->st_flags & SELTD_RESCAN)
1462 return;
1463 /*
1464 * Grab one of the preallocated descriptors.
1465 */
1466 sfp = NULL;
1467 if ((sfp = stp->st_free1) != NULL)
1468 stp->st_free1 = NULL;
1469 else if ((sfp = stp->st_free2) != NULL)
1470 stp->st_free2 = NULL;
1471 else
1472 panic("selrecord: No free selfd on selq");
1473 mtxp = sip->si_mtx;
1474 if (mtxp == NULL)
1475 mtxp = mtx_pool_find(mtxpool_select, sip);
1476 /*
1477 * Initialize the sfp and queue it in the thread.
1478 */
1479 sfp->sf_si = sip;
1480 sfp->sf_mtx = mtxp;
1481 STAILQ_INSERT_TAIL(&stp->st_selq, sfp, sf_link);
1482 /*
1483 * Now that we've locked the sip, check for initialization.
1484 */
1485 mtx_lock(mtxp);
1486 if (sip->si_mtx == NULL) {
1487 sip->si_mtx = mtxp;
1488 TAILQ_INIT(&sip->si_tdlist);
1489 }
1490 /*
1491 * Add this thread to the list of selfds listening on this selinfo.
1492 */
1493 TAILQ_INSERT_TAIL(&sip->si_tdlist, sfp, sf_threads);
1494 mtx_unlock(sip->si_mtx);
1495 }
1496
1497 /* Wake up a selecting thread. */
1498 void
1499 selwakeup(sip)
1500 struct selinfo *sip;
1501 {
1502 doselwakeup(sip, -1);
1503 }
1504
1505 /* Wake up a selecting thread, and set its priority. */
1506 void
1507 selwakeuppri(sip, pri)
1508 struct selinfo *sip;
1509 int pri;
1510 {
1511 doselwakeup(sip, pri);
1512 }
1513
1514 /*
1515 * Do a wakeup when a selectable event occurs.
1516 */
1517 static void
1518 doselwakeup(sip, pri)
1519 struct selinfo *sip;
1520 int pri;
1521 {
1522 struct selfd *sfp;
1523 struct selfd *sfn;
1524 struct seltd *stp;
1525
1526 /* If it's not initialized there can't be any waiters. */
1527 if (sip->si_mtx == NULL)
1528 return;
1529 /*
1530 * Locking the selinfo locks all selfds associated with it.
1531 */
1532 mtx_lock(sip->si_mtx);
1533 TAILQ_FOREACH_SAFE(sfp, &sip->si_tdlist, sf_threads, sfn) {
1534 /*
1535 * Once we remove this sfp from the list and clear the
1536 * sf_si seltdclear will know to ignore this si.
1537 */
1538 TAILQ_REMOVE(&sip->si_tdlist, sfp, sf_threads);
1539 sfp->sf_si = NULL;
1540 stp = sfp->sf_td;
1541 mtx_lock(&stp->st_mtx);
1542 stp->st_flags |= SELTD_PENDING;
1543 cv_broadcastpri(&stp->st_wait, pri);
1544 mtx_unlock(&stp->st_mtx);
1545 }
1546 mtx_unlock(sip->si_mtx);
1547 }
1548
1549 static void
1550 seltdinit(struct thread *td)
1551 {
1552 struct seltd *stp;
1553
1554 if ((stp = td->td_sel) != NULL)
1555 goto out;
1556 td->td_sel = stp = malloc(sizeof(*stp), M_SELECT, M_WAITOK|M_ZERO);
1557 mtx_init(&stp->st_mtx, "sellck", NULL, MTX_DEF);
1558 cv_init(&stp->st_wait, "select");
1559 out:
1560 stp->st_flags = 0;
1561 STAILQ_INIT(&stp->st_selq);
1562 }
1563
1564 static int
1565 seltdwait(struct thread *td, int timo)
1566 {
1567 struct seltd *stp;
1568 int error;
1569
1570 stp = td->td_sel;
1571 /*
1572 * An event of interest may occur while we do not hold the seltd
1573 * locked so check the pending flag before we sleep.
1574 */
1575 mtx_lock(&stp->st_mtx);
1576 /*
1577 * Any further calls to selrecord will be a rescan.
1578 */
1579 stp->st_flags |= SELTD_RESCAN;
1580 if (stp->st_flags & SELTD_PENDING) {
1581 mtx_unlock(&stp->st_mtx);
1582 return (0);
1583 }
1584 if (timo > 0)
1585 error = cv_timedwait_sig(&stp->st_wait, &stp->st_mtx, timo);
1586 else
1587 error = cv_wait_sig(&stp->st_wait, &stp->st_mtx);
1588 mtx_unlock(&stp->st_mtx);
1589
1590 return (error);
1591 }
1592
1593 void
1594 seltdfini(struct thread *td)
1595 {
1596 struct seltd *stp;
1597
1598 stp = td->td_sel;
1599 if (stp == NULL)
1600 return;
1601 if (stp->st_free1)
1602 uma_zfree(selfd_zone, stp->st_free1);
1603 if (stp->st_free2)
1604 uma_zfree(selfd_zone, stp->st_free2);
1605 td->td_sel = NULL;
1606 free(stp, M_SELECT);
1607 }
1608
1609 /*
1610 * Remove the references to the thread from all of the objects we were
1611 * polling.
1612 */
1613 static void
1614 seltdclear(struct thread *td)
1615 {
1616 struct seltd *stp;
1617 struct selfd *sfp;
1618 struct selfd *sfn;
1619
1620 stp = td->td_sel;
1621 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn)
1622 selfdfree(stp, sfp);
1623 stp->st_flags = 0;
1624 }
1625
1626 static void selectinit(void *);
1627 SYSINIT(select, SI_SUB_SYSCALLS, SI_ORDER_ANY, selectinit, NULL);
1628 static void
1629 selectinit(void *dummy __unused)
1630 {
1631
1632 selfd_zone = uma_zcreate("selfd", sizeof(struct selfd), NULL, NULL,
1633 NULL, NULL, UMA_ALIGN_PTR, 0);
1634 mtxpool_select = mtx_pool_create("select mtxpool", 128, MTX_DEF);
1635 }
Cache object: c81863f3061a0e1058182fdb4f4306a2
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